1. Graduate School of Frontier Biosciences; Osaka University; 1-3 Yamadaoka Suita Osaka 565-0871 Japan
2. Department of Macromolecular Science; Graduate School of Science, Osaka University; 1-1 Machikaneyama-cho Toyonaka Osaka 560-0043 Japan
3. Quantitative Biology Center, Riken; 1-3 Yamadaoka Suita Osaka 565-0871 Japan